Navigation systems are generally mounted on vehicles and are used as terminal devices for vehicles that help drivers travel and reach his/her destination with ease by displaying a road map for the drivers or searching a route to the destination.
An automotive navigation system being currently widely used is an apparatus that identifies a current position of a car or a user in real time by calculating signals received from satellites using a Global Positioning System (referred to as ‘GPS’, hereinafter), converts relevant data in a database, which contains map information and traffic information built previously, corresponding to the current position into image/voice information in association with the database, and displays the converted image/voice.
The automotive navigation system includes a GPS receiver to calculate a current position of a car. The automotive navigation system obtains information on current speed, time and position of the car through the use of the GPS receiver and provides a user with navigation information based on such information.
However, when the current position using GPS signals is calculated, there normally occurs an error of tens of meters because of characteristics of the GPS signals. Therefore, when such an error is used to calculate the current position on a map, the current position may be erroneously displayed on a point out of a road, on a rooftop of a building or the like.
In order to resolve such a drawback, a typical automotive navigation system employs a map matching method when calculating a position of a car. According to the map matching method, a current position is compared to road data under an assumption that the car is driving on a road. When the difference between the current position and the road data falls within a predetermined range, the automotive navigation system determines that the car is driving along the relevant road and forcibly corrects the current position to a point on a road nearest to the current position.
Korean Laid-Open Patent Publication No. 10-2010-0067578 suggests an apparatus and method for map matching of a moving object. It discloses a map matching method to correct a position coordinate of a moving object such as a vehicle moving on a road, wherein a position of the moving object is corrected into a point on the road when coordinate data of the road does not exist on a map data and thus it is not easy to make a conventional map matching.
Japanese Laid-Open Patent Publication No. 2002-318121 discloses a navigation system, which is capable of determining a current position of a moving object when the moving object moves into an indoor facility. First, the navigation system determines a current position of the moving object by performing a map matching on an output data from a stand-alone sensor and an output data from a GPS apparatus using a map data while the moving object is moving. Thereafter, when it is detected that the current position of the moving object is located within an indoor facility, the navigation system performs a map matching on the output data from the stand-alone sensor using a map data to determine the current position of the moving object.
Generally, when a user terminal such as the automotive navigation system receives a positioning data or measures its current position, a position of a user is displayed by performing a map matching on the positioning data to network data (for example, such as a node or link) nearest to the position of the user. When performing the map matching, however, even in the case that the user is located indoors, especially, at a specific indoor space, the user terminal renders a positioning result to map-match to nearest network data. Accordingly, it is not possible to precisely reflect a real position of the user who is actually located indoors on the map.